Psychophysiological deficits are important in understanding both schizophrenia and the aging process. The Psychophysiology Core is designed to provide a multi-factorial assessment of several important domains of psychophysiological, information processing and attentional functions of subjects in the CRC. This Core is an extension of the Motor Function Core which has been productively in place during the past three years of the CRC's existence. The newly expanded Psychophysiology Core test battery reflects our growing awareness of the central role of psychomotor, attentional, and information processing deficits in understanding the schizophrenia and other psychotic disorders in general and late-life psychoses in particular. The Psychophysiology Core will provide an initial comprehensive battery which assesses eight measures from four domains of psychophysiological function including: motor function, startle plasticity, pupillometry and cerebral event-related potentials. Schizophrenia patients have been found to have deficits in all four domains and these deficits are related to the symptoms, course, and outcome of schizophrenia. In addition, these psychophysiological measures have been related to specific neural substrates that may be impaired in psychosis. The Psychophysiology Core will serve as a data acquisition and hypothesis testing module of the CRC. Since psychophysiological deficits across all of the four domains are associated with both schizophrenia and aging, this database will support the CRC themes of examining late-life psychosis cross-sectionally and longitudinally, and will add to our knowledge of treatment effects and predictors. The Psychophysiology Core will test formal hypotheses pertaining to the four Center-wide themes: (1) age of onset of schizophrenia; (2) different late-onset psychoses; (3) clinical outcome; and (4) treatment outcome, and in doing so will be able to address the following specific questions: (1) How does age of onset treated as a continuous variable correlate with deficits on psychophysiologic dependent measures in schizophrenia? (2) What psychophysiological deficits are observed across different late-onset psychoses? (3) What psychophysiological deficits are observed cross sectionally at baseline in patients who represent a variety of outcomes? and (4) Do the psychophysiological measures on admission to the treatment protocols predict or correlate with the subsequent treatment responses? In addition, the eight dependent measures of the Psychophysiology Core will be utilized to answer questions about cross-Core hypotheses relating to how these psychophysiological measures relate to specific deficits in clinical state, neuropsychological function, and brain imaging abnormalities. Finally, specific psychophysiological measures that appear to tap into similar processes and neural substrates will be correlated with each other. Via this cumulative effort, the significance of psychophysiological information processing and attentional abnormalities in late-life psychosis will be defined and clarified.